Yaseen K. Abass, and A. A. Shihab. “ Class AK-Manifold of Concircular Curvature Tensor (V)”. Tikrit Journal of Pure Science 28, no. 1 (February 20, 2023): 101–104. Accessed March 29, 2024. https://tjps.tu.edu.iq/index.php/tjps/article/view/1272.